APPLICATION OF EXTENDED PLUG NOZZLE NOISE SUPPRESSION THEORY TO A SMALL TURBOJET ENGINE.
WILLIAMS RESEARCH CORP WALLED LAKE MICH
Pagination or Media Count:
Small scale tests showed the best overall results when 1 The area of the plug equals the annular flow area between the plug and nozzle. 2 A plug length ranging from zero to two nozzle diameters before the start of the termination. 3 A plug termination of a 10 degree straight taper. This configuration reduced the noise by about 10 db at a pressure ratio of 3.0 with a corresponding thrust loss of about 6. On the WR2-2 turbojet engine, the extended plug nozzle similarly reduced exhaust noise although to a smaller extent. A 3 db reduction in noise was achieved with a corresponding thrust loss of 4, however, the engine was only operated up to an exhaust pressure ratio of 2.5. Another nozzle showed a 1 12 db reduction with a corresponding thrust increase of 5. The extended plug nozzle approach to jet noise suppression shows promise. Author
- Jet and Gas Turbine Engines